You have just installed your Cel-Fi or weBoost Signal Booster system, but the bars on your mobile device haven't moved. According to your smartphone, you're not getting a better signal after installing your new signal booster.

Fortunately, the booster may be working just fine — even if you don't see a change in bars. Even if you installed your device correctly and experience significantly improved service, you may not see any difference in the number of bars on your smartphone. Or, browsing web pages on the internet may be slow due to poor signal quality on your 4G, or 3G cellular router.

Comparing your boosted WiFi signal strength against your cell phone's initial performance is a better way to confirm that the signal booster is working. For example, if previously you had no coverage in this area or experienced dropped calls and now you have no problems, you can say without a doubt that you have a better signal thanks to your Cel-Fi or weBoost Smart Signal Booster!

The truth is that the number bars might not change. The reading on your handset or tablet does not always show raw signal strength. Almost all mobile manufacturers have proprietary algorithms to calculate signal strength, signal-to-noise ratio, and channel loading, among other things. The result is different signal readings between devices. Your iPhone signal result might not agree with your Samsung smartphone's result.

Before we dig into how to troubleshoot your signal booster, let's do a little background on signal boosters.

What Is a Signal Booster or Cellular Repeater?

A signal booster is a device used to improve weak cellular signals, call quality, and data speeds, particularly in rural areas and dense urban districts. You may have also heard these devices called amplifiers or repeaters. 

The booster works by pulling in a weak cellular signal from the original source, then rebroadcasting an amplified signal to the desired reception location. The booster cannot create a signal by itself — it must have an existing signal to receive and amplify.

Most signal boosters come with three essential components: an indoor antenna, an amplifier, and an external antenna. 


Where can I buy a signal booster?

Novotech offers cellular signal boosters from two of the top manufacturers in the market: Cel-Fi and weBoost. From weBoost, we carry the popular Home and Drive X-Line, and from Cel-Fi, we have the Pro, Go, Go-X, and Quatra

Cel-Fi and weBoost provide signal boosters for both home and business use — including at the enterprise level. As cellular device use continues to increase, many users discover that their cell signal degrades. More cell towers and providers use ever stronger signals to offer coveted “nationwide” coverage — but an unintended consequence can be weakened service for some customers.

The problem is particularly apparent inside buildings. For whatever reason, your service provider’s signal cannot adequately penetrate inside the building. Anyone indoors may find the signal weakening and dropping, which is inconvenient and frustrating. If your business depends on reliable cell service, you want to be able to maximize your that to prevent losing customers and ensure everything at your company runs smoothly.

If you have difficulty receiving a sufficiently strong cell signal for your mobile device, like your smartphones or tablets, a signal booster may be the answer to your problem. Keep reading to learn some of the most common signal booster problems and how to troubleshoot them.

Troubleshooting Your Cel-Fi or weBoost Signal Booster

Novotech, in partnership with Cel-Fi and weBoost, created this handy page to help you troubleshoot the most common issues found after installing a signal booster, including:

  1. Slow data speeds
  2. Spotty or inconsistent coverage
  3. Dropped calls

If you just installed your signal booster, move directly to the troubleshooting steps below. If your signal booster has been installed for a while, however, check the hardware to ensure everything is in place.

Signal boosters require very little maintenance, but it’s always possible that something has damaged one of the exterior mounts or cables on an antenna outside the building. It’s also possible an internal antenna has become misaligned or damaged as well.



Deciphering What Raw Signal Strength Means 

Before starting to troubleshoot, you need to know how to find and understand your raw signal strength.

The raw signal strength determines whether your handset is getting a signal from the coverage unit (CU) — the device that rebroadcasts the cell signal. Signal strength is measured in decibel milliwatts (dBm). 

With the signal booster coverage unit plugged in, go to the location of your CU and dial the Field Test Mode code for your phone. Remember the number that appears. 

Now, unplug your CU and note the change in signal strength. It might take a few minutes for your phone's readings to update.

Keep in mind, a smaller negative number means a stronger signal. For example, if your signal strength jumps from -111 dBm to -100 dBm, your signal is 10 times stronger with Cel-Fi than without it.

While the signal strength changes might seem slight, even a reading three digits smaller than before is two times stronger. The cellular scale is not 0 to 100 dBm. Instead, the usable cellular LTE signal ranges from -120 dBm (barely usable) to -60 dBm (the best possible). 

Here is a simple chart to give you an idea of just how much this "tiny" improvement really is:

  • How much stronger the signal really is
  • Improvement in handset’s signal value in dB (with Cel-Fi CU on)
  • Do you see how much stronger the signal is now?
  • Can you detect the improvement in your smartphone's signal value with the signal booster turned on?

If you can’t see any difference, maybe the signal booster isn’t working as expected. Here is where the troubleshooting steps come in.

Why Is My Cell Phone Booster Not Working?

There are two reasons your cell phone signal booster isn’t working. Either it is experiencing overload, or there is an oscillation problem. Most of the time, the solution is simple and can result in improved loading times, call quality, and connection speed.

To start troubleshooting, determine your current signal strength by following the steps below.

Step #1 - How to Find Signal Strength on a Mobile Device

Watch this informative video, then troubleshoot your device using the instructions for your smartphone brand and operating system.

Ste #2 - How to Determine Your Raw Signal Strength


iOS 10.3.1 and newer


  1. Dial *3001#12345#*
  2. Select “LTE”
  3. Select “Serving Cell Meas” signal strength will be displayed as “RSRP0”


  1. Dial *3001#12345#*
  2. Select “UMTS”
  3. Select “Serving Cell Meas” signal strenght will be displayed as “RSCP0”

iOS versions OLDER than 10.3.1

  1. Dial *3001#12345#*
  2. Hold the Power/Lock button until you see “Slide to power off”. Do not power off, but release the power button.
  3. Hold the Home button until the phone goes back to your home screen. At this time you should now see your raw signal strength instead of bars on the top left of your handset.
  4. To go back to bars, dial *3001#12345#* and tap the home button to Exit Field Test Mode.


Most Android Devices

  1. Go to Apps
  2. Settings
  3. General
  4. About Device
  5. Status
  6. You will find Signal Strength on this screen


  1. Dial *#0011#
  2. The Signal Indicator will be displayed as RI or RSRP.

Samsung RI RSSP

How to Resolve Signal Booster Overload

Amplifier overload can occur in areas where multiple cell service providers send out powerful signals. The overload causes an immediate reduction in signal boosting strength. It might correct on its own, but it’s more likely the amplifier maxes out before it can correct. 

Even if the signal booster self-corrects, the event potentially leads to a continuous state of signal drop and recalibration.

You can try three things to resolve the overload and recommence service.



1. Adjust the External (Outdoor) Antenna

If you are using a directional antenna, adjust the external (outdoor) antenna in small amounts to reduce the signal it receives. Stop between movements to check for overload warnings and determine the status of the cell signal strength. 

You want your external antenna where the amplifier operates at full capacity to distribute the signal evenly without dropping. It can take patience, but this method is the best first step.

If adjusting the external antenna doesn’t work, move to the next step.



2. Try an Attenuator

If your problem is caused by multiple cell towers located very close to your building, try an attenuator. This device decreases the incoming signal strength by resting on or touching your antenna cable. However, anyone who already has a weak signal will lose signal strength, too, so be sure it isn't the opposite problem.

The next step should be approached as a last resort.



3. Switch the Amplifier

You might need to purchase an amplifier that can handle stronger signals. The price varies substantially, but it may be what you need to get your cellular signal working optimally.

It's worth the investment if this is what's causing your problem.

How to Resolve Oscillation Issues

Oscillation means the signal is bouncing back and forth between two points. Sometimes, broadcasting a boosted signal from an interior antenna to an exterior one results in a feedback loop, resulting in oscillation. 

A feedback loop happens when a signal booster tries to self-correct by reducing the signal boosting output on the affected band. It reduces the coverage area to stop the signal from transmitting to the exterior antenna. 

You might see a warning indicating amplifier oscillation. This means the antenna hasn’t been able to resolve the problem independently.

There are three steps you can take to try and resolve the oscillation issue.



1. Check the Directional Antenna Position Relative to the Building

Your directional antenna must face away from the building. If it’s pointed toward part of the roof or across a roof ridge, it’s probably picking up ambient signals radiating from inside. Shift the antenna to point away from the roof.



2. Move the Interior and Exterior Antennas

CAUTION: Always switch off the power to the amplifier before moving the antennas.

Attempt to reposition both interior and exterior antennas so they are farther apart. To optimize performance, you can spread the antennas further apart horizontally. However, you can try to separate them vertically if you lack space. Place them where you receive the ideal signal strength. 

Spacing the antennas vertically can be more effective than horizontal positioning, but both have advantages. Once you have made the necessary adjustments, switch the amplifier power on and check for continuing oscillation.

If you still see a problem, try another antenna position.



3. Shield the Exterior Antenna

This is the step of last resort. 

Move the external antenna somewhere to align with a large object, like an air conditioning unit or chimney. You need to put significant mass between the antenna and the rest of the building.

If your exterior antenna is indoors, shield it with something made of metal like aluminum foil, or place it behind a filing cabinet. If you want to block the signal entirely, set the exterior antenna behind the interior antenna.

If you still experience issues, reach out to Novotech for help. As the leading provider of signal boosters, we're here to ensure you can successfully troubleshoot any problems you may have with your Cel-Fi or weBoost device.



Support & Warranty

We provide pre- and post-sales consultation for your Cel-Fi or weBoost device set-up and installation. We partner with some of the top installation companies around the world to schedule installation for your device. 

Novotech is committed to providing superior customer service for your Cel-Fi Signal Booster. We have over 20 years of experience and can help you resolve your issue efficiently. If you're still having problems with your signal booster, please contact us for help. You can find support and warranty information here.



Novotech Is a Leading Provider of Signal Boosters

The use of signal boosters isn’t limited to inside buildings or houses. Sometimes you need to boost the signal strength inside a vehicle, such as a boat, RV, truck, SUV, car, or fleet vehicle. Novotech provides specialized Cel-Fi and weBoost signal boosters for vehicular use. 

Whether your problem is a weak signal inside your business or within your service vehicle, Novotech provides a solution to improve your coverage, boost data speeds, and reduce or eliminate dropped calls and connections.

If your signal booster doesn’t function as expected after installation, try the troubleshooting steps we provided in this article. 

  • Determine your signal strength.
  • Find out if you have an amplifier overload or an oscillation issue.
  • Use the appropriate troubleshooting steps to try to resolve the problem.

As always, you are welcome to contact Novotech for assistance. Industry leaders trust us as a top distributor of cellular signal booster hardware and services for homes, businesses, and vehicles. 

For more information on the topic, review our article "What is a Signal Booster"

Unsure of what signal booster to buy? Check out our Cel-Fi Signal Booster Comparison Chart or our weBoost Canada Signal Booster Comparison Chart